2 week 12 Flashcards
functions of blood? (5)
- transports gases, nutrients, hormones, metabolic wastes.
- regulates composition of interstitial fluid.
- restricts fluid loss at injury sites via blood clotting.
- defends against toxins and pathogens.
- regulates body temp by absorbing and redistributing heat.
what are the constituents of blood?
- plasma: 55%
- erythrocytes: 45%
- buffy coat (WBC + platelets): less than 1%
what is plasma made of?
- 92% water
- ions, organic molecules, trace elements, gases
- organic molecules = proteins like albumins (60%), globulins (36%), fibrinogen (4%)
where are most plasma proteins made? and does plasma have a greater or lesser concentration of proteins than interstitial fluid?
- liver
- greater
where do blood cells and platelets come from? what is this process called?
- stem cells
- hematopoiesis
main function of erythrocytes? how do they obtain their energy?
- transport oxygen and contain carbonic anhydrase needed for transport of carbon dioxide.
- no nucleus or organelles… obtain energy via glycolysis
describe the structure of a hemoglobin molecule
- identical alpha and beta subunits
- 4 heme groups (meaning it can bind 4 oxygens)
- iron in centre of heme group; non-covalent
what is hematocrit? average for males vs females?
- ratio of erythrocytes : total blood volume (centrifuged sample)
- males: 40-54
- females: 37-47
what is polycythemia? why can this be dangerous?
- adaptive response; higher hematocrit in low-oxygen environments.
- i.e., ppl living at high altitudes can have 60 hematocrit.
- dangerous because makes blood have high viscosity = clots.
describe the life cycle of erythrocytes (6)
- formation = erythropoiesis (in red bone marrow)
- stimulated by erythropoietin (released from kidney in response to low oxygen)
- no cell division of mature RBCs
- short life span = 120 days
- replace 2–3 million RBCs/second
- old RBCs filtered by spleen (and liver)
which portion of the RBC is eliminated? where does it go?
- heme!
- converted to bilirubin and excreted
what is…
a) aplastic anemia
b) nutritional anemia
c) pernicious anemia
d) renal anemia
a) drugs destroy stem cells
b) inadequate iron, folic acid, vitamin b12
c) deficiency in intrinsic factor like GI tract
d) kidney failure = low erythropoietin
what causes anemia? (5)
- genetics
- parasitic infections
- drugs
- autoimmune reactions (hemolytic)
- excessive blood loss (hemorrhagic)
what are the 4 blood types we discussed and what are the differences among them?
- A: has A antigens and antiB antibodies [42%]
- B: has B antigens and antiA antibodies [9%]
- AB: has A and B antigens; no antibodies (universal recipient!) [3%]
- O: has no antigens and antiA and antiB antibodies (universal donor!) [46%]
what is the main function of WBC? what is its structure like? (3)
- immune system
- nucleated
- several types